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Silicone encapsulants from WACKER are effective for the potting and encapsulation of electronic control units, sensors, printed circuit boards, semiconductor devices or microchips. Potting or encapsulation provides efficient protection from the environment, assisting in reliable operation and the lifetime of electronic devices.

We offer one and two component WACKER products for potting and encapsulation applications. Silicone gels offer minimal thermal stress on sensitive parts and ensure that the device will work properly even when exposed to extreme temperature fluctuations or strong vibrations. For sensor applications, gels characterised by particularly low volatility and low bleed are becoming increasingly important.

Features & Benefits

  • High thermal shock resistance
  • Low shrinkage
  • Good adhesion including to polymer housings
  • Low outgassing
  • Low uncured-silicone bleed
  • Formulations from Shore 00-55 to A80
  • Transparent versions available


Product Cure Mechanism Curing Time Colour Characteristics
Elastosil RT 601 Addition 24h at 23°C Transparent General-purpose potting compound. Manufacture of solar panels. RI=1.409. Food compliant.
Elastosil RT 604 Addition 24h at 23°C
30 min at 70°C
8 min at 100°C
5 min at 150°C
Transparent Highly transparent. Food-compliant. Softer lower viscosity than RT 601.
Elastosil RT 607 Addition 24h at 23°C Reddish Brown Flame-retardant. Good heat resistance. Food-compliant.
Silgel 612 Addition 8 h at 23°C
15 min at 100°C
5 min at 150°C
Transparent General-purpose potting compound. Manufacture of solar panels. RI=1.404. Pronounced inherent tack. Low bleed. Good damping properties.
Elastosil RT622 Addition 30 min at 150°C Reddish Brown All round potting compound. Suitable for technical mouldings and encapsulation of components.
Elastosil RT K Condensation 7h at 23°C Grey General purpose potting compound. Excellent flowability
Elastosil RT 428 Condensation 24h at 23°C Reddish Brown Thermally conductive
Semicosil 961 TC Addition 5h at 23°C
5 min at 100°C
Yellow Thermally conductive gap filler. Shear-thinning. Easy-dispensing. Non-slump. Soft and tacky rubber.


Product Mix ratio Viscosity mPas Hardness Tensile Strength N/mm2 Elongation % Temp Range Pot Life Volume Resistivity Ohm.cm Dielectric Strength kV/mm Thermal Conductivity W/m k
Elastosil RT 601 9:1 3,500 Shore A 45 6.0 100 150°C 90 mins 10^15 23 0.2
Elastosil RT 604 9:1 800 Shore A 25 1.0 100 150°C 90 mins 10^15 23 0.2
Elastosil RT 607 9:1 10,000 Shore A 55 3.5 100 210°C 80 mins 10^15 23 0.4
Silgel 612 1:1 1,000 Very soft gel -50° to 180°C 150 mins 10^15 >23 0.2
Elastosil RT622 9:1 12,000 Shore A 27 6.5 550 60 mins
Elastosil RT K 100:4 7,000 Shore A 45 2.0 130 -50° to 180°C 150 mins 10^14 23 0.3
Elastosil RT 428 12,000 Shore A 65 6.0 90 -50° to 200°C 100 mins >10^13 23 0.3
Semicosil 961 TC 1:1 130,000 Shore A 25 -50° to 180°C 60 mins 10^13 8 2.3
  • Last updated: October 2018
  • Version: 1.3

Statements, technical information and recommendations contained herein are based on tests we believe to be reliable but they are not to be construed in any manner as warrantees expressed or implied. The user shall determine the suitability of the product for his intended use and the user assumes all risk and liability whatsoever in connection therewith.